mercurial: Changelog

rhg: add a config option to fall back immediately This is useful for debugging the behavior of the "default" `hg` in tests without having to manually substitute the fallback path.

rhg: stop shadowing `exit` function This will be useful for the next patch which needs it.

config: add alias from `hg help rhg` to `hg help rust` This will make using `rhg` more user-friendly and features more discoverable.

rhg: add `config.rhg` helptext This will make using `rhg` more user-friendly and features more discoverable.

config: fix indentation of some`share-safe` options This makes the output much more readable.

rust-status: query fs traversal metadata lazily Currently, any time the status algorithm needs to read a directory from the filesystem (because the stat-only optimization is not available), it also stats each directory entry eagerly. Stat'ing the entries is only needed in a few cases (like when checking the mtime of a directory for caching): this patch creates a wrapper struct `DirEntry` that only stats the directory entry it represents when needed. Excerpt of an `strace` before this change on Mozilla Central: ``` openat(AT_FDCWD, ".", O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_DIRECTORY) = 3 newfstatat(3, "", {st_mode=S_IFDIR|0755, st_size=3540, ...}, AT_EMPTY_PATH) = 0 getdents64(3, 0x55dc970bd440 /* 139 entries */, 32768) = 5072 statx(3, ".hg", AT_STATX_SYNC_AS_STAT|AT_SYMLINK_NOFOLLOW, STATX_ALL, {stx_mask=STATX_ALL|STATX_MNT_ID, stx_attributes=0, stx_mode=S_IFDIR|0755, stx_size=772, ...}) = 0 [... 135 other successful `statx` calls] getdents64(3, 0x55dc970bd440 /* 0 entries */, 32768) = 0 close(3) = 0 ``` After this change: ``` openat(AT_FDCWD, ".", O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_DIRECTORY) = 3 newfstatat(3, "", {st_mode=S_IFDIR|0755, st_size=3540, ...}, AT_EMPTY_PATH) = 0 getdents64(3, 0x561567c10190 /* 139 entries */, 32768) = 5072 getdents64(3, 0x561567c10190 /* 0 entries */, 32768) = 0 close(3) = 0 ```

rust-status: make `DirEntry` attributes clearer

perf-unbundle: do a quick and dirty fix to make it run on more commit Without this change, the perf commands fails within the f67741e8264b::18415fc918a1 range (boundary excluded). Check inline comment for details. With this fix, the command is able to run on this range, with a slightly different behavior (as no revset is "uninlined"). However this is still much better than not being able to run anything in this range. Especially because that range do see some performance regression for unbundle.